Stator

Stator is an experimental JavaScript engine written in Rust, designed to be embedded in browser-like environments such as Chromium via a stable C FFI layer.

Architecture

┌──────────────────────────────────────────┐
│           Chromium / Embedder            │
│   (C++ content layer, Node.js, etc.)     │
└───────────────────┬──────────────────────┘
                    │  C ABI  (stator.h)
┌───────────────────▼──────────────────────┐
│              stator_ffi                  │
│  cdylib / staticlib — opaque C handles   │
│  stator_isolate_create / _gc / _destroy  │
└───────────────────┬──────────────────────┘
                    │  Rust rlib
┌───────────────────▼──────────────────────┐
│             stator_core                  │
│  Heap · GC · Objects · Parser · IR · VM  │
└──────────────────────────────────────────┘

Additional crates:

Crate	Type	Purpose
stator_core	rlib	Engine internals (heap, GC, IR, VM)
stator_ffi	cdylib + staticlib	Stable C API for embedders
st8	bin	Interactive JavaScript shell (like V8's d8)
stator_test262	bin	Test262 conformance harness runner

Requirements

Tool	Minimum version
Rust (stable)	1.85 (edition 2024)
Cargo	bundled with Rust

Build

# Build all crates
cargo build

# Build in release mode
cargo build --release

The C FFI artifacts are written to:

• target/release/libstator_ffi.a — static library (Linux / macOS)
• target/release/libstator_ffi.so — shared library (Linux)
• target/release/stator_ffi.lib / stator_ffi.dll — Windows equivalents

Test

cargo test

st8 CLI

st8 is the Stator command-line shell, analogous to V8's d8. It executes JavaScript files, evaluates inline snippets, and supports Chrome DevTools Protocol (CDP) inspection.

# Build the shell
cargo build --bin st8

# Execute a JavaScript file
cargo run --bin st8 -- file.js

# Evaluate an inline expression
cargo run --bin st8 -- -e '1 + 2'

# Run with Chrome DevTools inspector on port 9229
cargo run --bin st8 -- --inspect file.js

# Run and pause before the first statement
cargo run --bin st8 -- --inspect-brk file.js

Example session:

$ echo 'print(6 * 7)' > hello.js
$ cargo run --bin st8 -- hello.js
42

Built-in globals

Global	Description
print(...args)	Prints arguments joined by a space, followed by a newline
console.log(...args)	Alias for print
WebAssembly	Full WebAssembly JS API namespace

Additional options

Flag	Description
-e '<code>'	Evaluate an inline JavaScript expression
--inspect[=port]	Start CDP inspector (default port: 9229)
--inspect-brk[=port]	Start inspector and pause before first statement
--emit-snapshot=<path>	Serialize built-in globals to a snapshot file
--snapshot=<path>	Load globals from a snapshot for faster startup
--jit-stats	Print JIT compilation statistics after execution

Embedding example

See examples/mini_browser for a minimal C++ application that demonstrates how Chromium's content layer would create and destroy isolates via the C FFI API.

Roadmap

See the open issues and project board for the current roadmap and planned milestones.

License

Stator is distributed under the MIT License.